Everyone knows leafy greens are healthy, but they can have significantly different nutritional profiles.
We’re going to take a quick side-by-side look at spinach and lettuce.
Note that all data on this page is per 100 gram raw serving of each food (although cooking spinach a bit can improve nutrient absorption).
Table of Contents
Nutritional Value Comparison of Lettuce and Spinach
There are many varieties of lettuce. Their nutritional value is a bit different from each other, but overall pretty similar.
I chose to look at the nutritional data for romaine lettuce, as it’s arguably the most popular variety.
Let’s start with the macronutrient profiles:
| Romaine Lettuce | Spinach | |
|---|---|---|
| Energy (kcal) | 17 | 23 |
| Protein (g) | 1.2 | 2.9 |
| Total Lipid (g) | 0.3 | 0.4 |
| Carbohydrate (g) | 3.3 | 3.6 |
| Fiber (g) | 2.1 | 2.2 |
| Sugars (g) | 1.2 | 0.4 |
Since leafy greens have a high water content, it’s not surprising that they both have very few calories.
However, the one big difference is that spinach has significantly more protein. While 1.7 grams per 100 gram serving doesn’t seem like a lot, it does add up if you have multiple servings.
Vitamins and Minerals in Lettuce vs Spinach
The table below shows the vitamins and minerals in a 100 gram serving of both vegetables.
The RDA value is the general recommended daily amount for an adult that I included to make comparing data simpler, but your specific RDA may vary based on age and gender.
| RDA | Romaine Lettuce | Spinach | |
|---|---|---|---|
| Vitamin K (µg) | 75 | 102.0 | 483.0 |
| Vitamin A (µg) | 900 | 436.0 | 469.0 |
| Folate (µg) | 400 | 136.0 | 194.0 |
| Manganese (mg) | 2.3 | 0.2 | 0.9 |
| Vitamin C (mg) | 90 | 4.0 | 28.1 |
| Potassium (mg) | 2000 | 247.0 | 558.0 |
| Magnesium (mg) | 400 | 14.0 | 79.0 |
| Iron (mg) | 18 | 1.0 | 2.7 |
| Riboflavin (mg) | 1.3 | 0.1 | 0.2 |
| Vitamin B-6 (mg) | 1.3 | 0.1 | 0.2 |
| Vitamin E (mg) | 15 | 0.1 | 2.0 |
| Calcium (mg) | 1200 | 33.0 | 99.0 |
| Phosphorus (mg) | 700 | 30.0 | 49.0 |
| Thiamin (mg) | 1.2 | 0.1 | 0.1 |
| Sodium (mg) | 1500 | 8.0 | 79.0 |
| Zinc (mg) | 11 | 0.2 | 0.5 |
| Niacin (mg) | 16 | 0.3 | 0.7 |
| Choline (mg) | 550 | 9.9 | 19.3 |
| Selenium (µg) | 55 | 0.4 | 1.0 |
| Copper (mg) | 900 | 0.0 | 0.1 |
| Vitamin B-12 (µg) | 2.4 | 0.0 | 0.0 |
| Vitamin D (µg) | 15 | 0.0 | 0.0 |
Both lettuce and spinach are great sources of a variety of nutrients:
- Vitamin K
- Vitamin A
- Folate
- Potassium
These foods are among the best plant-based sources of vitamin K, a fat soluble vitamin. Too much vitamin K can interfere with blood-thinning medication (source), but anyone else who’s healthy and not taking medication typically doesn’t need to worry about the high amount. There’s no upper limit for vitamin K because:
…no adverse effects associated with vitamin K consumption from food or supplements have been reported in humans or animals.
Aside from those, spinach has more vitamins and minerals. Specifically, spinach is significantly higher in:
- Manganese
- Vitamin C
- Magnesium
- Iron
While lettuce and spinach both provide a lot of vitamins and minerals per serving, spinach clearly has a stronger nutrient profile.
Lettuce vs Spinach: Which is Healthier?
I’ll be very clear: both lettuce and spinach are very healthy foods that most people should be trying to eat more of.
However, if you could only pick one, spinach is a healthier food for most people. It has more protein, and similar or higher values of most vitamins and minerals compared to lettuce.
There’s one exception: people with a history of kidney stones. While this is not medical advice, some doctors may recommend that people with a high risk of kidney stones avoid foods with lots of oxalate.
It just so happens that certain leafy greens like spinach and swiss chard have the highest levels of oxalate and could potentially contribute to kidney stones. Lettuce does have some oxalate, but less than spinach. Again, that’s a discussion to have with your doctor if it’s relevant to you, but it’s worth mentioning here.
